<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    // var age = 18
    // age = 81
    // console.log(age)

    // var age = 18, uname = 'zs', test = 'qwer'
    // console.log(age)
    // console.log(uname)
    // console.log(test)

    // 尽量不要用 
    // address = '成都'
    // console.log(address)
  </script>
</body>
</html>